8626( 4) - 07/08/02 09:28 - [ 1] PROPOSAL FOR HUBBLE SPACE TELESCOPE OBSERVATIONS ST ScI Use Only ID: 8626 Version: 4 Check-in Date: 24-Apr-2000 06:33:45 1.Proposal Title: Spatially Resolved Spectroscopy of APM08279+5255 ------------------------------------------------------------------------------------ 2. Proposal For 3. Cycle GO 9 ------------------------------------------------------------------------------------ 4. Investigators Contact? PI: Sara Ellison European Southern Observatory - Chile CoI: Dr. Max Pettini Institute of Astronomy N CoI: Dr. Raghunathan Srianand IUCAA N CoI: Mr. Bastien Aracil IAP N CoI: Dr. Rodrigo Ibata ESO N CoI: Dr. Geraint Lewis University of Washington N CoI: Dr. Patrick Petitjean IAP N ------------------------------------------------------------------------------------ 5. Abstract We propose to obtain spatially resolved, high resolution spectra of the z=3.911 BAL quasar, APM 08279+5255. This ultra-luminous QSO is a triply imaged gravitationally lensed system with image separations of 0.38 -- 0.15 arcsec. Ground- based observations of this bright source have revealed a rich absorption spectrum caused by both intervening material and the complex QSO environment and BAL flows. The proposed STIS spectrum, which will spatially resolve the individual quasar images, is a unique opportunity to probe the numerous intervening systems on sub-kpc scales, providing: 1) a sensitive probe of the structure of intervening galaxy halos and metal line systems on scales of ~ 0.2 -- 1.6 kpc h^-1, their kinematics and spatial extents, 2) multiple sightlines through the complex BAL flow on parsec scales, yielding information on ionization, kinematics and metal enrichment, We also request 5 orbits with WFPC2 in order to detect and measure the centroid of the lensing galaxy; this will provide the necessary information to remove the degeneracy in the present gravitational lensing models. ------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 2] Observations Description ------------------------ sectionSpectroscopy: Observing Requirements and Instrument Setup We propose to use the G750M grating with a 0.2 arcsec wide slit oriented along the the major axis between the 2 bright components (A-B) of the lensed system. Since the third component (C) is not exactly positioned along this axis, we will offset by 0.02 arcsec perpendicular to the slit so as to centre on the faintest image. In order to fulfil the scientific goals laid out in the previous section, we require full wavelength coverage from 5930 -- 8670 Angstrom with S/N = 40 -- 50 and resolution 0.56 AA pixel in order to: (i) detect 1Sigma equivalent width differences in intervening systems between all 3 lines of sight of ~ 20 -- 25 mAngstrom, which represents 10% accuracy in W_Lambda determinations of typical Mg II systems. The geometry of this system is such that we have the opportunity to probe 3 sightlines through each absorber from a single slit placement. Moreover, the separation of the 3 images probes 2 different scales for each intervening system (Table 1), therefore adequate S/N to accurately determine abundance differences in A, B and C is very important. The exposure times calculated here are for component C, the S/N ratios for A and B will be considerably higher. In addition, with the G750M grating, the strong absorption lines will be resolved and with the S/N ratios proposed here we will detect velocity differences of 30 km/s. For the BAL systems the observed frame equivalent width limit will be W_Lambda ~ 0.05Angstrom. (ii) obtain accurate line profiles for the z = 1.06 metal lines (e.g. Mg II, Fe II, Ti II, Ca II) in order to investigate the kinematics along different sightlines through the lensing galaxy. In order to cover the full wavelength range with the G750M grating, a minimum of 5 settings is required. The central wavelengths required to achieve this coverage are presented in Table 2. sectionExposure times and Required Orbit Calculation APM 08279+5255 is visible for 56 minutes per orbit. Table 2 presents calculated exposure times needed to obtain S/N = 40 -- 50 for a 52 * 0.2 arcsec slit. The exposure times were calculated using the on-line ETC and based on the faintest component, C (R=17.8). Since we will be using a 0 nd2 slit, we require only a Target Acquisition manouevre with no need for an extra Acquisition Peakup. Using the STIS F28*50LP filter, a S/N = 40 ratio of the brightest component (A) would be obtained in 0.5 seconds. Given that we will be dominated by overheads rather than exposure time, we suggest a 2 second Acquisition exposure which will yield S/N (A) = 87 and S/N (B) = 74 (calculated from the ETC). Including overheads (guide star acquisition, target acquisition, tilt changes, wavecals etc.) we calculate the number of orbits presented in Table 2. begintable begintabularlcccl Central Lambda (Angstrom) & Range (Angstrom) & Exp. time (s) & Orbits & Examples of covered lines , 6215 & 5930 - - 6500 & 1.4 * 10 ^4 & 5 & Si IV, Mg II, N V, 6765 & 6480 -- 7050 & 1.2 * 10 ^4 & 4 & Si IV(BAL), Ti II, 7315 & 7030 -- 7600 & 1.2 * 10 ^4 & 3 & C IV(BAL), Fe II, Mg II , 7865 & 7580 -- 8150 & 1.6 * 10 ^4 & 6 & C IV, Ca II , 8415 & 8130 - - 8700 & 2.1 * 10 ^4 & 7 & Mg II, Ca II, endtabular captionTilt settings and exposure times required with the G750M setting to obtain a S/N = 40 -- 50, based on calculations for C endtable sectionImaging: Observing Requirements and Instrument Setup To detect the lensing galaxy we propose to use WFPC2 with its FR533N linear ramp filter (LRF), with the quasar centered on WF2 at pixel position (337.06, 692.11), effectively providing a narrow band filter (central wavelength 4935Angstrom, width 63Angstrom). In this spectral region, the quasar flux is f_QSO = 6 * 10^-18 erg cm^-2 s^-1 AA^-1. An identical flux is expected from the lensing galaxy if it has V = 22, which, fortuitously, is the value of the present upper limit (Ibata et al. 1999), determined from a dark interval in the HIRES spectrum. If the lensing is due to the dominant Mg II absorber, we expect that galaxy to be an elliptical at z=1.06, with velocity dispersion ~ 200 km/s. Our aim is to reach a detection limit of V = 23.5, a magnitude below the Faber-Jackson luminosity ( V = 22.5) of the expected lens. With a total 8626( 4) - 07/08/02 09:28 - [ 3] system efficiency of 2\ the LRF to obtain ~ 400 e^- from a V = 23.5 galaxy; in the same time we will detect ~ 1600 e^- from the QSO, giving S/N ~ 9, from which we will be able to centroid any extended emission to better than 0 nd02. We will first obtain a short 10 second exposure with the FR533N LRF on WF2 at pixel position (337.06, 692.11), of the nearby 11th magnitude star (``S2'' in Lewis et al. 1999). This will allow us to construct a high S/N point-spread function (PSF). The coordinate frame of LRF exposures will be determined with respect to several bright stars in the field (see Figure 2 of Irwin et al. 1998), and the remaining flux from the QSO images. Contamination from the residual quasar emission will be subtracted using the PSF determined from the bright star. Real Time Justification ----------------------- None None Calibration Justification ------------------------- Additional Comments ------------------- ------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 4] TARGET LIST Fixed Targets ------------------------------------------------------------------------------------------------------------------------------------ Tar| Target | Target | Target |Coord | Radial | Flux data No | Name | Description | Position |Eqnx | Vel. | ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO- GALAXY, QSO RA=08H 31M 41.766S +/- 0.15", J2000 Z = R = 15.2+/-0.5 083142+52451 DEC=52D 45' 17.37" +/- 0.15", 3.911 F-CONT(6500)=3+/-0.5e-15 7 PLATE-ID=01HB Coordinate Source: GSC_SURVEY_PLATE 2 GSC3797-1900 CALIBRATION, POINT RA=8H 32M 28.6S +/- 0.15", J2000 B = 11.44 SPREAD FUNCTION DEC=52D 45' 34.34" +/- 0.15", PLATE-ID=01HB Coordinate Source: GUIDE_STAR_CATALOG 8626( 4) - 07/08/02 09:28 - [ 5] Visit: 01 Visit Priority: Visit Requirements: ORIENT 255D TO 258D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO-083142+ STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S 524517 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6252 1 2500 S POS TARG -0.02,-2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 21 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6252 1 3100 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 31 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6252 1 3100 S POS TARG -0.02, 0.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 41 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6252 1 3100 S POS TARG -0.02, 1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 51 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6252 1 3100 S POS TARG -0.02, 2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 6] Visit: 02 Visit Priority: Visit Requirements: ORIENT 255D TO 258D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO-083142+ STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S 524517 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6768 1 2500 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 21 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6768 1 3100 S POS TARG -0.02, 0.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 31 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6768 1 3100 S POS TARG -0.02, 1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 41 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 6768 1 3100 S POS TARG -0.02, 2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 45 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7283 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 51 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7283 1 3100 S POS TARG -0.02, 2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 7] Visit: 03 Visit Priority: Visit Requirements: ORIENT 255D TO 258D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO-083142+ STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S 524517 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7283 1 2500 S POS TARG -0.02, 1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 15 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7283 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 21 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7283 1 3100 S POS TARG -0.02, 0.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 25 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7283 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 31 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7283 1 3100 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 41 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7795 1 3100 S POS TARG -0.02,-2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 45 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7795 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 51 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7795 1 3100 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 8] Visit: 04 Visit Priority: Visit Requirements: ORIENT 255D TO 258D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO-083142+ STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S 524517 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7795 1 2500 S POS TARG -0.02, 0.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 15 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7795 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 21 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7795 1 3100 S POS TARG -0.02, 1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 25 CCDFLAT STIS/C ACCUM 52X0.2 G750M 7795 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 31 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 7795 1 3100 S POS TARG -0.02, 2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 41 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02, 2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 45 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8311 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 51 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02, 1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 9] Visit: 05 Visit Priority: Visit Requirements: ORIENT 255D TO 258D On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 1 QSO-083142+ STIS/C ACQ F28X50L MIRROR ACQTYPE=POINT 1 0.5 S 524517 CD P ------------------------------------------------------------------------------------------------------------------------------------ 11 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 2500 S POS TARG -0.02, 0.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 15 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8311 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 21 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 31 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02,-2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 35 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8311 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 41 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02,-2.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 45 CCDFLAT STIS/C ACCUM 52X0.2 G750M 8311 2 DEF CD ------------------------------------------------------------------------------------------------------------------------------------ 51 QSO-083142+ STIS/C ACCUM 52X0.2 G750M 8311 1 3100 S POS TARG -0.02,-1.00 524517 CD ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 10] Visit: 06 Visit Priority: Visit Requirements: On Hold Comments: Additional Comments: Exposures ------------------------------------------------------------------------------------------------------------------------------------ Exposure| Target |Instr | Oper. | Aper |Spectral|Central| Optional |Num| Time | Special Number | Name |Config| Mode |or FOV |Element |Waveln.| Parameters |Exp| | Requirements ------------------------------------------------------------------------------------------------------------------------------------ 10 GSC3797-190 WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 10 S POS TARG 0.000, 0.000 0 ------------------------------------------------------------------------------------------------------------------------------------ 11 GSC3797-190 WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 10 S POS TARG 0.224,-0.124 0 ------------------------------------------------------------------------------------------------------------------------------------ 12 GSC3797-190 WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 10 S POS TARG 0.350, 0.352 0 ------------------------------------------------------------------------------------------------------------------------------------ 13 GSC3797-190 WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=0.5 1 20 S POS TARG 0.169, 0.231 0 ------------------------------------------------------------------------------------------------------------------------------------ 20 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 800 S POS TARG 0.000, 0.000 524517 ------------------------------------------------------------------------------------------------------------------------------------ 30 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 800 S POS TARG 0.024,-0.124 524517 ------------------------------------------------------------------------------------------------------------------------------------ 35 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=0.5 1 1600 S POS TARG 0.350, 0.252 524517 ------------------------------------------------------------------------------------------------------------------------------------ 40 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 800 S POS TARG 0.269, 0.331 524517 ------------------------------------------------------------------------------------------------------------------------------------ 45 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=0.5 1 1600 S POS TARG -0.339, 0.243 524517 ------------------------------------------------------------------------------------------------------------------------------------ 50 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 800 S POS TARG -0.215,-0.085 524517 ------------------------------------------------------------------------------------------------------------------------------------ 55 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=0.5 1 1600 S POS TARG 0.333, 0.363 524517 ------------------------------------------------------------------------------------------------------------------------------------ 60 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=NO 1 800 S POS TARG -0.488, 0.488 524517 ------------------------------------------------------------------------------------------------------------------------------------ 65 QSO-083142+ WFPC2 IMAGE LRF LRF 4935 CR-SPLIT=0.5 1 1600 S POS TARG 0.143, 0.323 524517 ------------------------------------------------------------------------------------------------------------------------------------ 8626( 4) - 07/08/02 09:28 - [ 11] Summary Form for Proposal 8626 Item Used in this proposal ------------------------------------------------------------------------------------------------------------------------------------ Apertures F28X50LP 52X0.2 LRF ------------------------------------------------------------------------------------------------------------------------------------ Configurations STIS/CCD WFPC2 ------------------------------------------------------------------------------------------------------------------------------------ Opmodes ACQ ACCUM IMAGE ------------------------------------------------------------------------------------------------------------------------------------ Optional Parameters ACQTYPE=POINT CR-SPLIT=NO CR-SPLIT=0.5 ------------------------------------------------------------------------------------------------------------------------------------ Proposal Category GO ------------------------------------------------------------------------------------------------------------------------------------ Special Requirements ORIENT 255D TO 258D POS TARG -0.02,-2.00 POS TARG -0.02,-1.00 POS TARG -0.02, 0.00 POS TARG -0.02, 1.00 POS TARG -0.02, 2.00 POS TARG 0.000, 0.000 POS TARG 0.224,-0.124 POS TARG 0.350, 0.352 POS TARG 0.169, 0.231 POS TARG 0.024,-0.124 POS TARG 0.350, 0.252 POS TARG 0.269, 0.331 POS TARG -0.339, 0.243 POS TARG -0.215,-0.085 POS TARG 0.333, 0.363 POS TARG -0.488, 0.488 POS TARG 0.143, 0.323 ------------------------------------------------------------------------------------------------------------------------------------ Spectral Elements MIRROR G750M LRF ------------------------------------------------------------------------------------------------------------------------------------ Target Names QSO-083142+524517 CCDFLAT GSC3797-1900 ------------------------------------------------------------------------------------------------------------------------------------ Wavelengths 6252 6768 7283 7795 8311 4935 ------------------------------------------------------------------------------------------------------------------------------------